The present application relates to semiconductor device fabrication, and more particularly, to integrating non-volatile memory devices and logic devices on the same substrate.
A non-volatile memory device is one that can retain stored information in the absence of power. It is beneficial to integrate non-volatile memory device into logic circuits for high performance CPU, FPGA or neural network. However, the integration of non-volatile memory devices with logic devices has always been a challenge due to the different requirements for the non-volatile memory devices, which store charge, and the logic devices which are commonly intended for high speed operation. The need for storing charge has been addressed mostly with the use of floating gate. The need for this unique floating gate makes integration of the non-volatile memory devices and the logic devices difficult. In addition, since current advanced logic technology is typically accomplished using a replacement gate (also called gate-last) process flow, a method that allows effectively integrating non-volatile memory devices and logic devices in a replacement gate process flow is highly desirable.